CHESHIRE Constabulary broke the law during an investigation into one of its own officers.

It acknowledged processing personal information without any legal justification, breaching the First Principle of the 1984 Data Protection Act.

The admission followed an inquiry in 2004 by the Information Commissioner, a body set up to protect personal information.

The offences were committed as part of an internal disciplinary investigation conducted by the force's professional standards department (PSD) between May 1998 and March 2000 into a serving police constable who was buying and selling imported cars. The officer left the police in 2000 following the conclusion of the investigation.

In November 1998, PSD officers unlawfully used police computers and programmes and BT's iTel facility to obtain the officer's home phone records, which showed calls made by the officer and by members of his family.

They then used the iTel facility to identify the people who had been called before using the constabulary's information system to identify any names or addresses that 'may be of interest' to the police.

All this action was taken in spite of the fact that a report in July 1998 had concluded that no criminal offences had been committed by the officer under scrutiny.

Cheshire Constabulary has refused to comment on the findings because of an ongoing investigation into the matter by its PSD, which is being supervised by the Independent Police Complaints Commission.